DISEASES OF RESPIRATORY PASSAGES AND ORUANS. 123 
to a moderate degree of heat, for the purpose of evaporation, a 
grease spot remained on the same; hence it is an agent that should 
never be used in pleurisy, nor in any disease occurring in the o-- 
gans of respiration. Dropsical diseases, supervening on influenza, 
are never benefited by cathartics, for they always lead to debility 
and prostration. Influenza is a disease of very prostrating char- 
acter; hence the proper plan of treatment is to sustain the vital 
power, by nourishing diet, tonics, and stimulants—ginger and 
golden seal. While commenting, however, on the linseed oil 
treatment, I do not wish to censure the owner of the animal; fez 
I should be throwing stones into glass houses, having myself, in 
furmer years, used and recommended this kind of oil for various 
diseases ; but, after many mishaps, I am satisfied that it is unsafe 
in the treatment of equine affections. 
PERICARDITIS (INFLAMMATION OF PERICARDIUM), 
(SOMETIMES CALLED “ HEART DISEASE.’’) 
The pericardium is a membranous sac, which surrounds and 
incloses the heart. It is composed of two layers, united by cel- 
lular tissue. The external layer is dense and fibrous, and is 
attached, by ligaments, to the sternum, or breast-bone and dia- 
phragm, and above to the roots of the large blood-vessels. The 
internal layer exhibits internally a smooth surface, like the lining 
membrane of the cavity of the chest. From this surface is secreted 
a serous fluid, which lubricates the heart, and protects it from the 
friction which would otherwise occur. The pericardium is a wall 
of defense for the heart, and keeps it in its proper position, 
Pericarditis signifies inflammation of the inner membrane of 
the pericardium. It is a disease which is almost unknown to the 
ordinary practitioner in this country, and entirely unknown to 
the husbandman; yet it is a disease that carries off a large number 
of horses and cattle, and often the parties concerned in the treat- 
ment and ownership of the animals do not even suspect the trus 
nature of the malady. After the inflammatory action of the per- 
icardium has reigned for several days, unsuspected and un- 
checked, an inordinate effusion from the serous lining takes place. 
We then have dropsy of the “heart-bag.” Water accumulates 
around the heart, which interferes with its action so as to put a 
vtop to circulation, and this results in the death of the animal. 
Pay carditis often accornpanies, or is the sequel of, pleurisy and 
